1. Field of the Invention
This invention relates to load blocks of the type used as a form of dunnage to prevent cargo from shifting in a truck or rail car, and more particularly to a collapsible, self-locking load block made from a one-piece blank of foldable sheet material such as paperboard.
2. Description of the Background Art
A background art search directed to the subject matter of the present invention conducted in the United States Patent and Trademark Office disclosed the following United States Letters Patent:
______________________________________ 1,108,045 1,997,905 2,507,929 2,609,136 2,684,153 3,043,488 3,708,101 3,767,066 3,842,757 3,985,242 4,148,396 4,248,350 ______________________________________
None of the patents found in the search discloses a collapsible, one-piece, self-locking load block, with different length, width, and height dimensions, that includes opposed pairs of walls forming a tubular structure, with a pair of interlocking internal center panels extending diagonally between opposed corners of the tubular structure, and that also includes openings adapted for insertion of a retaining member into the block to assist in maintaining the load block in different positions adjacent the cargo in a transportation vehicle.